A surgical instrument alignment guide comprising a mount (2) arranged to be coupled to a bone of a patient, an alignment rod (4), a guide rod (24) and an indicator (26). The alignment rod (4) has a first end pivotally coupled to the mount (2) such that the inclination of the alignment rod (4) relative to the mount (2) is adjustable. The guide rod (24) is couplable to a second end of the alignment rod (4) at an adjustable angle and orientation such that the guide rod (24) can extend transverse to the alignment rod (4). The indicator (26) is coupled to the guide rod (24) to indicate when the guide rod (24) lies at a desired angle relative to a horizontal axis. Also disclosed is a method of aligning a surgical instrument using the surgical instrument alignment guide.